1. Field of the Invention
The present invention relates to a pattern matching system that determines whether or not a plurality of images matches each other, and a targeted object pursuit system that pursues the movement of a specified targeted object within a plurality of images captured sequentially using the above pattern matching system.
2. Description of the Related Art
A pattern matching system that calculates the likeness between a plurality of images is known. The pattern matching is used for pursuit of a targeted object moving within a plurality of images captured sequentially.
In prior pattern matching, the likeness is calculated by the following operation. First, the captured image is divided into smaller image components and the luminance of the divided image components is detected. Second, the luminance level of each image component into which a first image is divided is compared to that of a corresponding image component, into which a second image of the same location but subsequent to the first image, is divided. Finally, a value based on the number of image components of which the luminance levels from the first and second images are in agreement with each other is calculated as the likeness between the first and second images.
The greater the number of image components that are compared, the greater the accuracy of the calculated likeness value suggesting whether or not the first and second images are in agreement with each other. However, the greater the number of compared image components also increases the size requirement, in bits, of the digital arithmetical unit necessary for the pattern matching system. On the other hand, even though a higher bit digital arithmetical unit is mounted, the capacity of the digital arithmetical unit is not always used completely.